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Newsletter of Penn Dutch Cow Care May 2005

Hi Folks,

With pasture season upon us, certain conditions may arise in your cows. I'd like to talk about one condition, grass tetany, which is rare but I have seen two cases in the last week. But we need to also remember that early in the pasture season there is a high risk of pasture bloat on legume rich pastures. This is usually seen a few cows that become bloated after the herd has been on legume pastures for a few days. To prevent this, feed dry hay before they go to pasture. If they don't want to eat dry hay and they just want to eat pasture, you need to at least get something into them prior to pasture. This can be baleage, grass silage, or corn silage. Basically anything that will help them feel a little fuller so they don't go out to lush legume pasture on an empty stomach. Even feeding grain can help them feel a little fuller - yet be careful with grain feeding when lush pasture is growing since rumen acidosis can occur in grazed cows when there is not enough effective (dry hay) fiber for their rumen to function properly. If cows get bloat due to legume pasture, most are responsive to giving a pint of vegetable oil and repeating it in 15-20 minutes. Make sure that you are walking the animal around in the 15-20 minutes to have the vegetable oil in good contact with the rumen contents. If the cow is bloated severely and goes down, it is generally too late and she will die very soon unless you stab them in the bloated rumen to relieve the intense pressure which is basically choking them off internally. Use a short, stiff knife and thrust it quickly and firmly into the uppermost part of the bloated area of the rumen, keep the knife in and turn your wrist slightly while it is in to let the bloat escape more quickly. Hold in place for a couple of minutes. This procedure should have to be done only once in a couple of years time. If more frequent, ask yourself how to prevent bloat rather than resorting to stabbing your cow.

What about grass tetany? Grass tetany also only occurs when there is lush growth of pasture; however, it can be any kind of pasture (not just legumes). It will likely be a fresh cow that has more metabolic needs than a later lactation cow. Its symptoms are somewhat like milk fever and in actuality they easily could occur together. The main symptoms are that of a stiffness of a leg or side (unlike milk fever), the cow will almost fall over but usually right herself up prior to falling over, but after this goes on a while she will lay down. However, when lying down, they are very uncomfortable doing it because the muscles in certain areas will be very stiff. They can also then all of a sudden get up with normal strength (unlike a milk fever) and this can go on for a while. They also will act a bit more agitated than usual (similar to early milk fever) and stay that way (whereas milk fever will become depressed and dull). Recent history of being in early pasture growth will aid in the diagnosis and its subsequent proper treatment. The treatment consists of correcting the metabolic disturbance by giving IV CMPK (calcium, magnesium, phosphorus and potassium), which is allowed for organic livestock since these are electrolytes when in a liquid solution. However, it can be darn difficult to hit a vein properly in a cow that wants to keep shifting around when it is standing while it also partially attempts to lay down. Just wait until it is down. Then put a halter on her and tie the halter to a non-mobile post. Don't tie it back to her leg like in milk fever because of the strength she can use to try to get free (and mess up your IV position of needle). Give the bottle at no higher than her backbone. If it is an older cow, continue into a second bottle and if you have a stethoscope handy, listen to the heart to make sure it is beating regularly (it may be at a quicker rate, but it should be beating totally regularly) while you give the entire second bottle. By the end, the cow should be noticeably calmer than prior to treatment. Follow-up treatment would be to give "pink pills" -- the regular laxative type pills since they are predominantly magnesium oxide. Epsom salt follow up would also be OK since that is magnesium sulphate.

Cows left untreated and found down and unable to rise will often show more severe neurologic symptoms such as paddling the ground area near them and have a staring expression. They then may continue into convulsions, coma or death (which can happen in a few hours). In the severe situation, give the IV treatment fairly slowly since the solution contains calcium and potassium as well and the animal's system at this point will be acutely sensitive to the effects of added potassium and calcium.

This condition is brought on by pastures that have low magnesium and/or high potassium. Magnesium absorption is reduced when the concentration of ammonia is high in the rumen (as with lush pasture of any sort). The combination of low magnesium pastures combined with rapid growth leads to this condition. Although rare, it could be seen right now, as I have witnessed twice within the week. Happy grazing!

Ben M. Stoltzfus, 648 Cambridge Rd., Honey Brook, has a 10 month old Jersey bull for sale. Should be ready for heifer breeding in a couple months. 717-768-3437

 

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www.bovinityhealth.com

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